Numerical study of momentum and heat transfer in a pulsed plane laminar jet

In this paper, we propose numerical solutions for a two-dimensional pulsed plane jet in unsteady laminar regime. At the exit of the nozzle, the pulsating flow is imposed with a uniform temperature T-o and a velocity u=u(0)(1+A sin(omegat)). Two cases are considered: the free and the wall pulsed plane jet. For the wall jet case, the wall may either be considered adiabatic or subjected to a uniform temperature. Equations are treated with an appropriate finite difference method. The effect of the important governing parameters, such as the amplitude and the frequency of the pulsation, the Reynolds and Grashof numbers on the flow behavior are also investigated in detail. The results obtained show that the pulsation affects the flow in a vicinity region of the nozzle to reach the same asymptotic regime than the steady jet. The results also indicate that the initial development of the jet is considerably accelerated and the entrainment in the first diameters is enhanced. (C) 2003 Elsevier Ltd. All rights reserved.